News Release

What Would a Great Earthquake do to the Buildings in Downtown Los Angeles?

—Tall, Older, High-Rise and Wood-Frame Buildings Could Collapse—

A great earthquake along the southern San Andreas Fault could cause many tall buildings to collapse in Los Angeles, explains USGS earthquake expert Dr. Ken Hudnut in a new video interview.

Older brick buildings, commercial and industrial concrete buildings, many wood-frame buildings, especially multi-story apartment buildings with tuck-under parking, and even a few high-rise steel buildings are vulnerable to the strong ground motions of great earthquakes.

In the video, Dr. Hudnut explains the impact to buildings in Los Angeles depicted in the magnitude 7.8 earthquake in the ShakeOut science scenario.

"For the first time, we went through a process of calculating the ground motions of a great Southern California earthquake and reviewing those results with structural engineers," said Dr. Hudnut.

"What we achieved with the ShakeOut science scenario is a new level of understanding of ground motions and also agreement with structural engineering experts that tall building collapses are quite a realistic possibility in a big earthquake along the San Andreas fault and in Los Angeles."

The ShakeOut science scenario is the most comprehensive analysis ever of what a major Southern California earthquake would mean and is being used as the basis for The Great Southern California ShakeOut Nov. 12-18, which includes the largest earthquake preparedness drill in United States history on Nov. 13. In the scenario, the earthquake would kill 1800 people, injure 50,000, cause $200 billion in damage, and have long-lasting social and economic consequences.

Ground motion simulations and comparisons were performed through a collaboration with the

Southern California Earthquake Center, funded by the National Science Foundation.

You can check out Dr. Hudnut's interview in episode 73 of CoreCast. You can view other video interviews, see earthquake animations and impacts, download high-resolution imagery and much more, all related to the USGS science behind the Great Southern California ShakeOut, all in one place: www.usgs.gov/shakeout.

Nearly five million people have already signed up to take part in the ShakeOut. Don't be left out, sign up for ShakeOut at www.shakeout.org.

USGS provides science for a changing world. For more information, visit www.usgs.gov.